Just like cellulose, lignin and fats, proteins are renewable raw materials. However, their potential for the chemical industry remains untapped. Research groups of the Institute for Technological Design and Packaging named after Fraunhofer IVV, Germany, hopes to change this. The scientists’ idea is to use the promising techno-functional properties of plant proteins for industrial applications.
Although plant-based proteins played a key role in the chemical industry a century ago, such as as a binder or adhesive, their use has declined since the boom in the petrochemical industry. TeFuProt partners aim to change this and obtain proteins for industrial use from agricultural waste. The goal of this bioeconomic approach is to counter the scarcity and long-term rise in the price of fossil raw materials and the use of renewable oil as an alternative.
Processing agricultural raw materials such as rapeseed results in a large amount of protein. Such proteins are a by-product of the extraction of rapeseed oil. Residual protein by-products – rapeseed meal and rapeseed cake – have so far been used primarily as food in animal husbandry. But this use is limited due to the bitter substances they contain.
Due to their functional properties, such as the ability to form foams, gels and films, as well as to retain water, the protein fractions of rapeseed cake have great potential for a wide range of technical applications. They are ideal as additives for paints, varnishes, adhesives, lubricants, building materials, detergents and polymers.
Plant proteins open the door to the development of new, organic, bio-based products with improved properties. It also reduces our dependence on fossil resources and promotes sustainable production.Andreas Fetzer, scientist at the Fraunhofer Institute for Technological Design and Packaging
To harness the full potential of rasp, scientists have conducted research. The goal is to isolate proteins from rapeseed meal and cake and develop the necessary processes. In addition, biologists were responsible for protein modification and pre-formulation.
Also, as part of the study, the scientists analyzed the techno-functional properties of vegetable proteins from rapeseed – solubility, foaming and emulsification, as well as the properties of film formation.
The film-forming properties, in particular, have shown themselves to be particularly good. “When drying proteins dissolved in water, to which a biological plasticizer has been added, the water evaporates in the Petri dish and the proteins are crosslinked to form a stable film. Thus, proteins are generally suitable as alternative binders in paints and varnishes, wood stains or parquet coatings, which usually contain petroleum-based raw materials. Acrylates, for example, can be replaced with protein drugs, ”explains Fetzer. In addition, proteins show the ability to effectively bind dyes or act as barriers. This demonstrated the added benefit of protein-based coatings, especially in the woodworking industry: the colorants effectively prevented “bleeding” from the wood.
Fetzer and his colleagues have successfully reconstituted four types of protein using four completely different processes. Scientists defatted, ground and dissolved rapeseed cake in water. The mixture is then centrifuged to separate solids from liquids. Thereafter, the aqueous extract is purified. The recovered protein isolates have a protein content of over 90%.
The work of German scientists has led to promising products, some of which are already available as prototypes. These include biodegradable films as packaging material for detergent bags as well as wood fiber board from residues and binders modified with rapeseed protein. Fire resistant insulation foams for the construction industry or molded foams for packaging, fiber protection and dye transfer inhibitors in environmentally friendly laundry detergents, thickeners for lubricants or lacquer binders and additives in universal wood cleaners round out the list of innovative, sustainable products.